WO 2008/014766 A1 describes a device for monitoring at least one operating parameter of a wheel set bearing of a rail vehicle. The device comprises a sensor and a transmitting unit that are arranged with the bearing ring rotating on the end of the wheel axle and a generator unit with a co-rotating and a rotationally locked generator element for supplying energy to the sensor and transmitting unit. The co-rotating generator element is a Wiegand element that is arranged on the end of the wheel axle, while the second cooperating generator element is formed by magnets that are fixed in location. This device cannot be integrated directly into the bearing.
In EP 0 397 309 A2, a bearing arrangement is described in which a rotational speed sensor is integrated. In a two-row rolling bearing, a pole wheel is mounted on the rotating inner ring between the two rows of rolling bodies. The pole wheel is formed on its periphery by a magnetic ring with alternately arranged poles of the magnets. A Hall sensor is provided in the outer ring in the radial orientation relative to the pole wheel. The pole wheel can also be constructed from a ferromagnetic material with extended poles (e.g., teeth). Then a magnet is required in the sensor arrangement. Because the sensor is provided on the stationary bearing part, supplying it with energy is not problematic.
From DE 695 24 014 T2, a wheel bearing of a rail vehicle with an integrated rotary current generator is known. The energy generated by the generator is stored in a battery. The generator is arranged in the inner space between the two conical rollers and comprises a rotor that rotates with the inner ring and the axle and a stator that is fixed in place on the outer ring. The rotor comprises a row of permanent magnets that are arranged at equal distances on the ring area between the conical rollers in the peripheral direction. The poles of the permanent magnets are arranged radially and distributed around the ring with alternating polarity. As a whole, the stator is a sheet metal packet made from magnetic steel films with extended teeth each of which carries a wound coil. The three-phase stator winding is produced by a Y-connection of the coils.
From EP 0 402 240 A1, an inclined cylinder rolling bearing with an integrated motor is known. The rotor is connected to the inner ring and the stator is connected to the outer ring. This motor requires a large amount of axial packaging space.
From DE 25 05 802 A1, a rotational speed encoder integrated in a rolling bearing is known. The electrical induction rotational speed encoder comprises an annular rotor body that has a C-shaped cross section and is made from ferromagnetic material. This carries a multi-pole permanent magnet. In the open space in the rotor body there is an annular stator body with a coil body with a coil winding. The stator body also carries an annular toothed disk made from ferromagnetic material, wherein the teeth of the toothed disk are arranged opposite the permanent magnet of the rotor. The rotor and stator interact such that, for the relative rotation of the bearing rings in the coil, an electrical pulse sequence or alternating voltage corresponding to the rotational speed is induced that can be used in a circuit arrangement for determining and/or controlling the rotational speed of the shaft.
From JP 2008 174 067 A, a radial bearing with a sensor is known that reliably detects a load moment on the wheel. The sensor is so compact that it can be integrated into the bearing. Within the bearing there is a magnetic circuit whose air gap is changed by a load or force onto the wheel. This change in the magnetic flux is detected and evaluated.
From U.S. Pat. No. 7,362,023 B2, a rolling bearing is known that is equipped with an electric generator, a rotational speed sensor, and a wireless transmitting unit. The electrical generator is constructed like a claw pole generator. A multi-pole magnet is here arranged as a rotor on the inner or outer ring and carries a plurality of alternately polarized magnets distributed on its periphery. A magnetic ring that carries a coil in its interior is arranged as a stator opposite the permanent magnet multi-pole ring. The magnetic ring carries claws that mesh one in the other and extend from the side walls of the magnetic ring past the coil. The rotational speed sensor and the wireless transmitting unit are supplied by the generator. Rotational speed data is transmitted to the peripherals with the wireless transmitting unit.
DE 102010021160 A, which is a published application of one of the inventors and assigned to the assignee of the present invention discloses a claw pole generator integrated into a rolling bearing, and FIGS. 1 and 2 of this publication are reproduced as FIGS. 4 and 5 of the present application as “Related Art.” In FIGS. 4 and 5, a rolling bearing having an inner ring 101 and an outer ring 102 with rolling elements 103 located therebetween is shown. First and second claw pole generators 104, 105 are integrated into the rolling bearing between the inner and outer rings 101, 102. The claw pole generator includes a primary part 107 that is connected to one of the inner and outer bearing rings 101, 102, and in the illustrated embodiment, it is connected to the outer ring 102. Permanent magnets 108 are connected to the other of the inner ring and the outer ring 101, 102, opposite from the primary part 107 and form the secondary part 106. Here the permanent magnets are located on the inner ring 101. The magnets 108 are arranged spaced apart in the circumferential direction with alternating polarities, as shown. The primary part 107 includes a coil support/carrier 109 in which the coil 111 is located. Claw rings 112, 113 are arranged on opposite axial sides of the coil 111 on the support 109, and extend primarily in the radial direction. The claw rings 112, 113 have oppositely directed, axially extending, interdigitated claws 112a, 113a located in proximity to the permanent magnets 108. As the inner ring 101 is rotated relative to the outer ring 102, the alternating magnetic fields of the permanent magnets passing the opposite interdigitated claws 112a, 113a of the claw rings 112, 113 induce a current flow in the coil 111.